Error: QML module not found (QtQuick.Window), the problem is something to do with import paths??

[Damiangage]

I'm new to Qt and am trying for the first time to make a Qt Quick project, but I'm getting the following error from the default "blank slate" that I automatically get:

Line: 2: QML module not found (QtQuick.Window).

Import paths:
/usr/lib/x86_64-linux-gnu/qt5/qml

For qmake projects, use the QML_IMPORT_PATH variable to add import paths.
For Qbs projects, declare and set a qmlImportPaths property in your product to add import paths.https://snaptube.cam/ https://9apps.cam/
For qmlproject projects, use the importPaths property to add import paths.
For CMake projects, make sure QML_IMPORT_PATH variable is in CMakeCache.txt.
I get the impression the problem is something to do with path imports, but I'm not totally sure of which of the above "kinds of project" my project is (if I had to guess, it might be qmake), or how I would set the import path property for them.

I'm using PySide2 (version 5.15) in a virtual environment for this project with python 3.7.8, and as you may see from the error I'm using Linux. The code does run despite the error.

I installed Qt Creator via the online installer available from the website, but not the Qt version; I got the qt5 from the command line (through sudo apt install), and according to QtCreator's kit detection it's version 5.9.5, and it apparenely has a qmake location in /usr/lib/qt5/bin/qmake

I get the feeling this Qt version is the source of the issue somehow, but how do I solve it? I don't see the QML_IMPORT_PATH variable anywhere.